/*
 * WizardController.java 7 juin 07
 *
 * Sweet Home 3D, Copyright (c) 2007 Emmanuel PUYBARET / eTeks <info@eteks.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package com.eteks.sweethome3d.viewcontroller;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.net.URL;

import com.eteks.sweethome3d.model.UserPreferences;

/**
 * An abstract MVC for a wizard view. Subclasses should create a set of wizard steps
 * with subclasses of <code>WizardControllerStepState</code> and
 * and choose the first step with a call to <code>setStepState</code>.
 * The {@link #finish() finish} method will be called if user completes the wizard
 * steps correctly.
 * @author Emmanuel Puybaret
 */
public abstract class WizardController implements Controller
{
	/**
	 * The properties that the view associated to this controller needs. 
	 */
	public enum Property
	{
		BACK_STEP_ENABLED, NEXT_STEP_ENABLED, LAST_STEP, STEP_VIEW, STEP_ICON, TITLE, RESIZABLE
	}
	
	private final UserPreferences preferences;
	private final ViewFactory viewFactory;
	private final PropertyChangeSupport propertyChangeSupport;
	private final PropertyChangeListener stepStatePropertyChangeListener;
	
	private DialogView wizardView;
	// Current step state
	private WizardControllerStepState stepState;
	
	private boolean backStepEnabled;
	private boolean nextStepEnabled;
	private boolean lastStep;
	private View stepView;
	private URL stepIcon;
	private String title;
	private boolean resizable;
	
	public WizardController(UserPreferences preferences, ViewFactory viewFactory)
	{
		this.preferences = preferences;
		this.viewFactory = viewFactory;
		// Create a listener used to track changes in current step state
		this.stepStatePropertyChangeListener = new PropertyChangeListener()
		{
			public void propertyChange(PropertyChangeEvent ev)
			{
				switch (WizardControllerStepState.Property.valueOf(ev.getPropertyName()))
				{
					case FIRST_STEP:
						setBackStepEnabled(!stepState.isFirstStep());
						break;
					case LAST_STEP:
						setLastStep(stepState.isLastStep());
						break;
					case NEXT_STEP_ENABLED:
						setNextStepEnabled(stepState.isNextStepEnabled());
						break;
				}
			}
		};
		
		this.propertyChangeSupport = new PropertyChangeSupport(this);
	}
	
	/**
	 * Returns the view associated with this controller.
	 */
	public DialogView getView()
	{
		// Create view lazily only once it's needed
		if (this.wizardView == null)
		{
			this.wizardView = this.viewFactory.createWizardView(this.preferences, this);
		}
		return this.wizardView;
	}
	
	/**
	 * Displays the view controlled by this controller. 
	 */
	public void displayView(View parentView)
	{
		getView().displayView(parentView);
	}
	
	/**
	 * Adds the property change <code>listener</code> in parameter to this controller.
	 */
	public void addPropertyChangeListener(Property property, PropertyChangeListener listener)
	{
		this.propertyChangeSupport.addPropertyChangeListener(property.name(), listener);
	}
	
	/**
	 * Removes the property change <code>listener</code> in parameter from this controller.
	 */
	public void removePropertyChangeListener(Property property, PropertyChangeListener listener)
	{
		this.propertyChangeSupport.removePropertyChangeListener(property.name(), listener);
	}
	
	/**
	 * Sets whether back step is enabled or not.
	 */
	private void setBackStepEnabled(boolean backStepEnabled)
	{
		if (backStepEnabled != this.backStepEnabled)
		{
			this.backStepEnabled = backStepEnabled;
			this.propertyChangeSupport.firePropertyChange(Property.BACK_STEP_ENABLED.name(), !backStepEnabled,
					backStepEnabled);
		}
	}
	
	/**
	 * Returns whether back step is enabled or not.
	 */
	public boolean isBackStepEnabled()
	{
		return this.backStepEnabled;
	}
	
	/**
	 * Sets whether next step is enabled or not.
	 */
	private void setNextStepEnabled(boolean nextStepEnabled)
	{
		if (nextStepEnabled != this.nextStepEnabled)
		{
			this.nextStepEnabled = nextStepEnabled;
			this.propertyChangeSupport.firePropertyChange(Property.NEXT_STEP_ENABLED.name(), !nextStepEnabled,
					nextStepEnabled);
		}
	}
	
	/**
	 * Returns whether next step is enabled or not.
	 */
	public boolean isNextStepEnabled()
	{
		return this.nextStepEnabled;
	}
	
	/**
	 * Sets whether this is the last step or not.
	 */
	private void setLastStep(boolean lastStep)
	{
		if (lastStep != this.lastStep)
		{
			this.lastStep = lastStep;
			this.propertyChangeSupport.firePropertyChange(Property.LAST_STEP.name(), !lastStep, lastStep);
		}
	}
	
	/**
	 * Returns whether this is the last step or not.
	 */
	public boolean isLastStep()
	{
		return this.lastStep;
	}
	
	/**
	 * Sets the step view.
	 */
	private void setStepView(View stepView)
	{
		if (stepView != this.stepView)
		{
			View oldStepView = this.stepView;
			this.stepView = stepView;
			this.propertyChangeSupport.firePropertyChange(Property.STEP_VIEW.name(), oldStepView, stepView);
		}
	}
	
	/**
	 * Returns the current step view.
	 */
	public View getStepView()
	{
		return this.stepView;
	}
	
	/**
	 * Sets the step icon.
	 */
	private void setStepIcon(URL stepIcon)
	{
		if (stepIcon != this.stepIcon)
		{
			URL oldStepIcon = this.stepIcon;
			this.stepIcon = stepIcon;
			this.propertyChangeSupport.firePropertyChange(Property.STEP_ICON.name(), oldStepIcon, stepIcon);
		}
	}
	
	/**
	 * Returns the current step icon.
	 */
	public URL getStepIcon()
	{
		return this.stepIcon;
	}
	
	/**
	 * Sets the wizard title.
	 */
	public void setTitle(String title)
	{
		if (title != this.title)
		{
			String oldTitle = this.title;
			this.title = title;
			this.propertyChangeSupport.firePropertyChange(Property.TITLE.name(), oldTitle, title);
		}
	}
	
	/**
	 * Returns the wizard title.
	 */
	public String getTitle()
	{
		return this.title;
	}
	
	/**
	 * Sets whether the wizard is resizable or not.
	 */
	public void setResizable(boolean resizable)
	{
		if (resizable != this.resizable)
		{
			this.resizable = resizable;
			this.propertyChangeSupport.firePropertyChange(Property.RESIZABLE.name(), !resizable, resizable);
		}
	}
	
	/**
	 * Returns whether the wizard is resizable or not.
	 */
	public boolean isResizable()
	{
		return this.resizable;
	}
	
	/**
	 * Changes current state of controller.
	 */
	protected void setStepState(WizardControllerStepState stepState)
	{
		if (this.stepState != null)
		{
			this.stepState.exit();
			this.stepState.removePropertyChangeListener(this.stepStatePropertyChangeListener);
		}
		this.stepState = stepState;
		
		setBackStepEnabled(!stepState.isFirstStep());
		setNextStepEnabled(stepState.isNextStepEnabled());
		setStepView(stepState.getView());
		setStepIcon(stepState.getIcon());
		setLastStep(stepState.isLastStep());
		
		this.stepState.addPropertyChangeListener(this.stepStatePropertyChangeListener);
		this.stepState.enter();
	}
	
	protected WizardControllerStepState getStepState()
	{
		return this.stepState;
	}
	
	/**
	 * Requires to the current step to jump to next step. 
	 */
	public void goToNextStep()
	{
		this.stepState.goToNextStep();
	}
	
	/**
	 * Requires to the current step to go back to previous step. 
	 */
	public void goBackToPreviousStep()
	{
		this.stepState.goBackToPreviousStep();
	}
	
	/**
	 * Requires the wizard to finish. 
	 */
	public abstract void finish();
	
	/**
	 * State of a step in wizard. 
	 */
	protected static abstract class WizardControllerStepState
	{
		private enum Property
		{
			NEXT_STEP_ENABLED, FIRST_STEP, LAST_STEP
		}
		
		private PropertyChangeSupport propertyChangeSupport;
		private boolean firstStep;
		private boolean lastStep;
		private boolean nextStepEnabled;
		
		public WizardControllerStepState()
		{
			this.propertyChangeSupport = new PropertyChangeSupport(this);
		}
		
		/**
		 * Adds the property change <code>listener</code> in parameter to this home.
		 */
		private void addPropertyChangeListener(PropertyChangeListener listener)
		{
			this.propertyChangeSupport.addPropertyChangeListener(listener);
		}
		
		/**
		 * Removes the property change <code>listener</code> in parameter from this home.
		 */
		private void removePropertyChangeListener(PropertyChangeListener listener)
		{
			this.propertyChangeSupport.removePropertyChangeListener(listener);
		}
		
		public void enter()
		{}
		
		public void exit()
		{}
		
		public abstract View getView();
		
		public URL getIcon()
		{
			return null;
		}
		
		public void goBackToPreviousStep()
		{}
		
		public void goToNextStep()
		{}
		
		public boolean isFirstStep()
		{
			return this.firstStep;
		}
		
		public void setFirstStep(boolean firstStep)
		{
			if (firstStep != this.firstStep)
			{
				this.firstStep = firstStep;
				this.propertyChangeSupport.firePropertyChange(Property.FIRST_STEP.name(), !firstStep, firstStep);
			}
		}
		
		public boolean isLastStep()
		{
			return this.lastStep;
		}
		
		public void setLastStep(boolean lastStep)
		{
			if (lastStep != this.lastStep)
			{
				this.lastStep = lastStep;
				this.propertyChangeSupport.firePropertyChange(Property.LAST_STEP.name(), !lastStep, lastStep);
			}
		}
		
		public boolean isNextStepEnabled()
		{
			return this.nextStepEnabled;
		}
		
		public void setNextStepEnabled(boolean nextStepEnabled)
		{
			if (nextStepEnabled != this.nextStepEnabled)
			{
				this.nextStepEnabled = nextStepEnabled;
				this.propertyChangeSupport.firePropertyChange(Property.NEXT_STEP_ENABLED.name(), !nextStepEnabled,
						nextStepEnabled);
			}
		}
	}
}
